﻿/****************************************************************************************************
	Copyright (C) 2010 RapidWebDev Organization (http://rapidwebdev.org)
	Author: Eunge, Legal Name: Jian Liu, Email: eunge.liu@RapidWebDev.org

	This program is free software: you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation, either version 2 of the License, or
	(at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with this program.  If not, see <http://www.gnu.org/licenses/>.
 ****************************************************************************************************/

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Lucene.Net.Store;
using RapidWebDev.SearchIndex.Contract;
using Lucene.Net.Analysis;
using Lucene.Net.Analysis.Standard;
using Lucene.Net.Analysis.Snowball;
using Lucene.Net.Index;
using Lucene.Net.Documents;
using Lucene.Net.Search;
using RapidWebDev.Common;

namespace RapidWebDev.SearchIndex.DocumentHandlers
{
	/// <summary>
	/// The implementation to delete the indexing document.
	/// </summary>
	public class DeleteIndexDocumentHandler : IIndexDocumentHandler
	{
		private static readonly Analyzer defaultAnalyzer = new WhitespaceAnalyzer();

		/// <summary>
		/// Process index document for the index directory path.
		/// </summary>
		/// <param name="indexDirectoryPath"></param>
		/// <param name="indexDocMessage"></param>
		public void Process(string indexDirectoryPath, IndexDocMessage indexDocMessage)
		{
			try
			{
				System.IO.DirectoryInfo directoryInfo = null;
				if (!System.IO.Directory.Exists(indexDirectoryPath))
					directoryInfo = System.IO.Directory.CreateDirectory(indexDirectoryPath);
				else
					directoryInfo = new System.IO.DirectoryInfo(indexDirectoryPath);

				FSDirectory directory = FSDirectory.Open(directoryInfo);
				try
				{
					IndexWriter indexWriter = new IndexWriter(directory, defaultAnalyzer, IndexWriter.MaxFieldLength.UNLIMITED);
					try
					{
						BooleanQuery queryToRun = new BooleanQuery();
						Term idTerm = new Term(LuceneFields.DocumentId, indexDocMessage.DocumentId);
						queryToRun.Add(new TermQuery(idTerm), BooleanClause.Occur.MUST);
						Term typeTerm = new Term(LuceneFields.DocumentType, indexDocMessage.Type);
						queryToRun.Add(new TermQuery(typeTerm), BooleanClause.Occur.MUST);

						indexWriter.DeleteDocuments(queryToRun);
						indexWriter.Commit();
					}
					finally
					{
						if (indexWriter != null)
							indexWriter.Close();
					}
				}
				finally
				{
					if (directory != null)
						directory.Close();
				}
			}
			catch (Exception exp)
			{
				Logger.Instance(this).Error(exp);
				throw;
			}
		}
	}
}